10 IBS (irritable bowel syndrome) facts
In this article we will describe 10 IBS (irritable bowel syndrome) facts.
Key Points
- Irritable Bowel Syndrome (IBS) is a common functional gastrointestinal disorder characterized by chronic abdominal pain and altered bowel habits without any identifiable organic cause.
- It is diagnosed based on clinical criteria (Rome IV) and exclusion of other conditions.
- IBS is a long-term condition that can significantly affect quality of life, but it does not lead to serious disease or increase the risk of cancer.
- Management involves lifestyle changes, dietary modifications, pharmacological therapy, and addressing psychological factors.
- A multidisciplinary approach, including dieticians and mental health professionals, is often beneficial.
1. Definition
- Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder characterized by recurrent abdominal pain associated with changes in bowel habits, such as diarrhoea, constipation, or alternating between the two
- The symptoms must be present for at least six months, with recurrent abdominal pain on at least one day per week in the last three months, associated with two or more of the following (Rome IV criteria):
- Pain related to defaecation
- Change in stool frequency
- Change in stool form (appearance).
2. Epidemiology
- Prevalence: IBS affects approximately 10-15% of the global population, with similar figures in the UK. It is one of the most common reasons for gastroenterology referrals in primary care.
- Gender Distribution: IBS is more common in women than men, with a female-to-male ratio of about 2:1.
- Age of Onset: It can occur at any age but often begins in late adolescence or early adulthood.
- Geographical Variation: The prevalence is higher in Western countries, possibly due to dietary and lifestyle factors, but awareness and reporting differences may also contribute.
3. Risk factors
- Gender: Higher prevalence in females, potentially related to hormonal influences.
- Age: Younger adults, typically under the age of 50, are more commonly diagnosed.
- Psychological Factors: Anxiety, depression, and stress are strongly associated with the onset and exacerbation of IBS symptoms.
- Family History: There may be a genetic predisposition or learned behavior from family members.
- Diet: Certain foods, especially those that are high in FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols), can trigger symptoms in some individuals.
- Infections: History of gastrointestinal infections (post-infectious IBS) increases the risk, as does a history of antibiotic use.
4. Causes
The exact cause of IBS is not well understood, but it is believed to be multifactorial, involving:
- Altered Gut-Brain Axis: Dysfunction in the communication between the central nervous system and the enteric nervous system.
- Intestinal Motility Dysfunction: Abnormal bowel contractions leading to either diarrhea (increased motility) or constipation (decreased motility).
- Visceral Hypersensitivity: Increased sensitivity to pain or discomfort in the gastrointestinal tract.
- Gut Microbiota Alterations: Imbalance in the gut microbiome, potentially affecting gut motility and sensitivity.
- Psychosocial Factors: Stress, anxiety, and other psychological conditions can exacerbate or trigger symptoms.
- Dietary Triggers: Foods high in FODMAPs, caffeine, fatty foods, and alcohol may trigger or worsen symptoms.
5. Symptoms
The clinical presentation of IBS can vary widely but generally includes:
- Abdominal Pain: Cramping or discomfort that is often relieved by defecation.
- Altered Bowel Habits:
- IBS-D: Predominant diarrhoea
- IBS-C: Predominant constipation
- IBS-M: Mixed diarrhoea and constipation
- IBS-U: Unclassified
- Bloating and Abdominal Distension: Common, especially after meals.
- Mucus in Stool: Some patients may report the passage of mucus.
- Urgency or Incomplete Evacuation: Feeling of needing to rush to the toilet or not being able to completely empty the bowels.
6. Diagnosis
Clinical diagnosis
- Rome IV Criteria: Diagnosis is based on the presence of recurrent abdominal pain on average at least one day per week in the last three months, associated with two or more of the following:
- Related to defaecation
- Associated with a change in stool frequency
- Associated with a change in stool form
- Symptom History: Take a detailed history of symptoms, including onset, duration, and triggers.
- Red Flags: Rule out other serious conditions by looking for ‘red flag’ symptoms, such as:
- Unintentional weight loss
- Rectal bleeding
- Family history of colorectal cancer, IBD, or celiac disease
- Anemia or other laboratory abnormalities
Investigation
IBS is primarily a clinical diagnosis. Investigations are usually performed to exclude other conditions:
- Complete Blood Count (CBC): To check for anaemia or infection.
- C-Reactive Protein (CRP) or Erythrocyte Sedimentation Rate (ESR): To rule out inflammatory conditions like IBD.
- Coeliac Serology: To exclude coeliac disease.
- Stool Studies: To check for infections, particularly in patients with diarrhea-predominant IBS or recent travel.
- Thyroid Function Tests: To rule out hyperthyroidism (diarrhoea) or hypothyroidism (constipation).
- Faecal Calprotectin: Helps distinguish between IBS and IBD, as calprotectin levels are elevated in inflammatory conditions.
Differential diagnosis
- Inflammatory Bowel Disease (IBD): Crohn’s disease or ulcerative colitis may present with similar symptoms but usually have systemic features, weight loss, and abnormal laboratory results.
- Coeliac Disease: Can mimic IBS symptoms, particularly diarrhea and bloating. Serological tests and small bowel biopsy are diagnostic.
- Colorectal Cancer: Particularly in older adults with new onset of symptoms, weight loss, or anemia.
- Lactose Intolerance: Bloating, diarrhea, and cramps after consuming dairy products.
- Diverticular Disease: Can cause changes in bowel habits and abdominal pain, especially in older adults.
- Small Intestinal Bacterial Overgrowth (SIBO): May cause bloating, diarrhea, and malabsorption symptoms.
7. Treatment
Lifestyle and dietary modifications
- Dietary Changes:
- Low FODMAP Diet: Proven to reduce symptoms in many patients. This involves reducing intake of fermentable carbohydrates found in certain fruits, vegetables, and dairy products.
- Regular Meals and Smaller Portions: Can help minimise bloating and discomfort.
- Avoiding Triggers: Patients should identify and avoid foods that trigger symptoms, such as caffeine, alcohol, fatty foods, and artificial sweeteners.
- Physical Activity: Regular exercise has been shown to improve bowel motility and reduce stress.
- Hydration: Important, especially for patients with constipation.
Pharmacological
- Antispasmodics: (e.g. mebeverine, hyoscine) for abdominal pain and cramps.
- Laxatives: (e.g. polyethylene glycol, lactulose) for IBS-C, but avoid stimulant laxatives for long-term use.
- Anti-Diarrheal Agents: (e.g. loperamide) for IBS-D, taken as needed.
- Tricyclic Antidepressants (TCAs): (e.g., amitriptyline) at low doses for pain relief and modulation of gut motility.
- Selective Serotonin Reuptake Inhibitors (SSRIs): May be beneficial, particularly for patients with co-existing anxiety or depression.
- Probiotics: Can help restore the natural balance of gut flora, though evidence is mixed.
- Peppermint Oil: Has antispasmodic properties and may help alleviate symptoms.
Psychological
- Cognitive Behavioral Therapy (CBT): Effective for many patients, especially those with significant anxiety or stress.
- Gut-Directed Hypnotherapy: Has been shown to reduce symptoms in some patients.
8. Complications
- Quality of Life Impairment: IBS can significantly affect daily activities, work, and social interactions.
- Mental Health: Depression, anxiety, and other psychological issues are more prevalent in patients with IBS.
- Nutritional Deficiencies: Can occur due to restrictive diets or malabsorption, particularly in patients following strict exclusion diets without professional guidance.
9. Prognosis
- Long-Term Management: IBS is a chronic condition but does not lead to serious complications such as cancer or IBD.
- Symptom Fluctuation: Symptoms can wax and wane, with periods of remission and flare-ups.
- Good Prognosis with Management: Most patients can manage their symptoms effectively with lifestyle changes, dietary modifications, and appropriate pharmacotherapy.
10. Prevention
- Dietary Awareness: Educating patients about triggers and the benefits of a balanced, healthy diet can help prevent flare-ups.
- Stress Management: Encouraging stress-reducing activities such as exercise, mindfulness, and CBT may help in managing and preventing symptoms.
- Early Recognition and Treatment: Prompt recognition of symptoms and early intervention can prevent worsening and improve the quality of life.
- Probiotic Use: Regular use of certain probiotics may help maintain a balanced gut microbiome, though more research is needed to identify the most effective strains.
Summary
We have described 10 irritable bowel syndrome (IBS) facts. We hope it has been helpful.
Other resource
MyHSN IBS podcast (2024) – 6 min, 23 sec
